Files
element-call-custom/src/state/SessionBehaviors.ts
2026-01-28 14:29:16 +01:00

91 lines
2.5 KiB
TypeScript

/*
Copyright 2025 Element Creations Ltd.
SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
Please see LICENSE in the repository root for full details.
*/
import {
type CallMembership,
type LivekitTransportConfig,
type MatrixRTCSession,
MatrixRTCSessionEvent,
isLivekitTransportConfig,
} from "matrix-js-sdk/lib/matrixrtc";
import { fromEvent } from "rxjs";
import {
Epoch,
mapEpoch,
trackEpoch,
type ObservableScope,
} from "./ObservableScope";
import { type Behavior } from "./Behavior";
export const membershipsAndTransports$ = (
scope: ObservableScope,
memberships$: Behavior<Epoch<CallMembership[]>>,
): {
membershipsWithTransport$: Behavior<
Epoch<{ membership: CallMembership; transport?: LivekitTransportConfig }[]>
>;
transports$: Behavior<Epoch<LivekitTransportConfig[]>>;
} => {
/**
* Lists the transports used by ourselves, plus all other MatrixRTC session
* members.
* For completeness this also lists the preferred transport and
* whether we are in multi-SFU mode or sticky events mode.
* `advertisedTransport$` reads these values together, so bundling them avoids inconsistent state or
* excessive updates when using RxJS.
*/
const membershipsWithTransport$: Behavior<
Epoch<
{
membership: CallMembership;
transport: LivekitTransportConfig | undefined;
}[]
>
> = scope.behavior(
memberships$.pipe(
mapEpoch((memberships) => {
return memberships.map((membership) => {
const oldestMembership = memberships[0] ?? membership;
const transport = membership.getTransport(oldestMembership);
return {
membership,
transport: isLivekitTransportConfig(transport)
? transport
: undefined,
};
});
}),
),
);
const transports$: Behavior<Epoch<LivekitTransportConfig[]>> = scope.behavior(
membershipsWithTransport$.pipe(
mapEpoch((mts) => mts.flatMap(({ transport: t }) => (t ? [t] : []))),
),
);
return {
membershipsWithTransport$,
transports$,
};
};
export const createMemberships$ = (
scope: ObservableScope,
matrixRTCSession: MatrixRTCSession,
): Behavior<Epoch<CallMembership[]>> => {
return scope.behavior(
fromEvent(
matrixRTCSession,
MatrixRTCSessionEvent.MembershipsChanged,
(_, memberships: CallMembership[]) => memberships,
).pipe(trackEpoch()),
new Epoch(matrixRTCSession.memberships),
);
};